Daikin VRV 2 (R410A) RZQY16

[Palkoper]

Hi guys
Today I came on site and found DAIKIN VRV 2 with main circuit breaker off - D63 A . Checked condensing unit and diagnose inverter board faulty . Taken another the same board from same model and fitted . Changed main circuit breaker C 60 A and turned unit ON . Immediate switched unit off because varistor on main PCB board F2S start burning ... see the picture IMAG0008.jpg


I am very desperate what going on .... It looks like L3 Phase crossing with neutral somewhere but i am not sure . Please if anyone knows what could be problem please let me know or please send me some service manuals on my email Thank You very much .

[The Viking]

Lol,
Welcome to the world of destructive fault finding

As you just found out, these boards are quite sturdy and rarely fails by themselves. Normally there is another fault that knocks the inverter out.
Sorry.

Model is RXYQ by any chance?

First things to check; Is all the phases present and correct to the unit? Neutral and earth? All the phases present before the inverter? Neutral?
Compressor windings rings out OK? Not down to earth? (Make sure you got a proper Mega Ohm meeter for this and not a cheap multi meeter)

Then it is time to start checking if it will work...
With the compressor disconnected set the system to "code 28", Power transistor check mode.




After you got it to code 28 you measure the voltage between each phase coming out from the inverter (with the compressor disconnected) and neutral, if they all are fairly similar the inverter is likely to be OK.


Good luck,



.